From 5916d5f9b3347344a3d96ba6b54cf8e290eba96a Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 13 Mar 2020 13:49:51 +0100 Subject: [PATCH] bug: Annotate WARN/BUG/stackfail as noinstr safe Warnings, bugs and stack protection fails from noinstr sections, e.g. low level and early entry code, are likely to be fatal. Mark them as "safe" to be invoked from noinstr protected code to avoid annotating all usage sites. Getting the information out is important. Signed-off-by: Thomas Gleixner Reviewed-by: Alexandre Chartre Acked-by: Peter Zijlstra Link: https://lkml.kernel.org/r/20200505134100.376598577@linutronix.de --- arch/x86/include/asm/bug.h | 3 +++ include/asm-generic/bug.h | 9 +++++++-- kernel/panic.c | 4 +++- 3 files changed, 13 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/bug.h b/arch/x86/include/asm/bug.h index facba9bc30ca..fb34ff641e0a 100644 --- a/arch/x86/include/asm/bug.h +++ b/arch/x86/include/asm/bug.h @@ -70,14 +70,17 @@ do { \ #define HAVE_ARCH_BUG #define BUG() \ do { \ + instrumentation_begin(); \ _BUG_FLAGS(ASM_UD2, 0); \ unreachable(); \ } while (0) #define __WARN_FLAGS(flags) \ do { \ + instrumentation_begin(); \ _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \ annotate_reachable(); \ + instrumentation_end(); \ } while (0) #include diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h index 384b5c835ced..c94e33ae3e7b 100644 --- a/include/asm-generic/bug.h +++ b/include/asm-generic/bug.h @@ -83,14 +83,19 @@ extern __printf(4, 5) void warn_slowpath_fmt(const char *file, const int line, unsigned taint, const char *fmt, ...); #define __WARN() __WARN_printf(TAINT_WARN, NULL) -#define __WARN_printf(taint, arg...) \ - warn_slowpath_fmt(__FILE__, __LINE__, taint, arg) +#define __WARN_printf(taint, arg...) do { \ + instrumentation_begin(); \ + warn_slowpath_fmt(__FILE__, __LINE__, taint, arg); \ + instrumentation_end(); \ + } while (0) #else extern __printf(1, 2) void __warn_printk(const char *fmt, ...); #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN)) #define __WARN_printf(taint, arg...) do { \ + instrumentation_begin(); \ __warn_printk(arg); \ __WARN_FLAGS(BUGFLAG_NO_CUT_HERE | BUGFLAG_TAINT(taint));\ + instrumentation_end(); \ } while (0) #define WARN_ON_ONCE(condition) ({ \ int __ret_warn_on = !!(condition); \ diff --git a/kernel/panic.c b/kernel/panic.c index 85568bbfb12b..e2157ca387c8 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -680,10 +680,12 @@ device_initcall(register_warn_debugfs); * Called when gcc's -fstack-protector feature is used, and * gcc detects corruption of the on-stack canary value */ -__visible void __stack_chk_fail(void) +__visible noinstr void __stack_chk_fail(void) { + instrumentation_begin(); panic("stack-protector: Kernel stack is corrupted in: %pB", __builtin_return_address(0)); + instrumentation_end(); } EXPORT_SYMBOL(__stack_chk_fail);